I have leased 100 waves and got around 0.96 Miner Rewards for one week. Waves prices are not dropping but it is moving up very consistently. Last week it went up to 6.5+ and not around 5.5$. If you want to increase your waves then start buying in small quantity on a regular basis instead of waiting for the right price to buy.
For leasing your waves here is the guide found in google search - https://www.cryptocompare.com/mining/guides/how-to-mine-waves/
Here is the guide created by one of the forum member - https://bitcointalksearch.org/topic/create-a-waves-platform-walletlease-your-tokens-and-get-rewardedtrade-on-dex-1899154